This invention relates in general to container filling equipment and, more particularly, to a mechanism for holding a stack of nested containers and dispensing them one at a time for transport and filling. The invention also pertains to a method for holding and dispensing the containers for transport and filling during processing.
Many types of food products such as ice cream and other dairy items are packaged in containers which have a tapered sidewall. The containers are constructed with this configuration so that they may be packed and shipped in space-saving nested stacks. The nested container stack also provides a convenient method of loading the containers into a feed magazine or dispenser during filling operations. The feed magazine is positioned over a movable mechanism which transports the containers one-at-a-time to a filling station where the food or other product is introduced into the container. The filled container is subsequently sealed by application of a lid or other sealing device and further processed as needed..LS2
To achieve high speed filling and processing, the containers must be delivered reliably and at a high rate of speed from the magazine to a receptacle in a carrier plate for delivery to the fill station. Satisfactory performance, however, is difficult to achieve because the lowermost container must be perfectly positioned over the receiving receptacle and must be released from the magazine and arrive in the receptacle prior to cycling of the apparatus. Because the containers are not aerodynamically stable, they may tumble as they fall from the magazine, resulting in jamming of the apparatus and increased material losses and operational costs. Moreover, precise timing of the release of a container from the nested stack is difficult to accomplish because of frictional and vacuum forces holding the container to the stack. Failure to deliver the container to the waiting receptacle on time results in further material and operational losses.
Construction of a suitable feed magazine which provides rapid and accurate dispensing of containers is difficult because the magazine must support the container stack while at the same time releasing the lowermost container in the stack. To achieve higher delivery speeds and greater reliability, conventional magazines or feeders have utilized various elaborate mechanisms for accelerating the downward drop of the lowermost container. In one prior art device, an oscillating escapement engages the bottom cup in the magazine and pushes it downward from the supported remainder of the stack. Another feeder utilizes a vacuum cup assist to pull the released container downward from the stack while still another feeder utilizes a group of timed rotating feedscrews which engage the outwardly rolled rim of the container. The feedscrews both support the stack and accelerate the downward release of the container. The speed and reliability of each of these devices, however, is less than desired for use with many high-speed filling processes.